SU910400A1 - Apparatus for abrasive jet working of part surface - Google Patents

Description

I

The invention relates to the field of abrasive blasting of the surfaces of various products from ferrous and non-ferrous and non-metallic alloys (for cleaning from burns, scale, rust and other contaminants, as well as for preparing surfaces for anti-corrosion coatings, for work hardening, and with a suitable abrasive fine material and mode treatments for polishing).

The proposed device can be used to treat the inner surface of tubes of small diameter, for example, 1.4 mm or less, vryut up to capillary sections ..,

A device for abrasive blasting the surfaces of parts containing an abrasive tank with a hole for the abrasive air stream out of the tank is known, a nozzle is mounted inside the tank, the upper end of which is located above the level of the abrasive located in the tank with a gap with respect to the abrasive exit hole

jet having a hole in the bottom

for feeding abrasive into it 1. ..

The disadvantage of the device is the instability of its operation, especially with significant changes in the volume when the abrasive diverges and when its moisture content changes, the wellness is 4HHt, the composition of the fraction, etc.

The aim of the invention is the expansion of technological capabilities in the processing of internal surfaces of small parts.

10 diameter.

The goal is achieved by the fact that in the proposed device, a cork with a calibrated hole is installed inside the nozzle to feed the abrasive, and outside the nozzle above and below the holes for feeding the abrasive there are protective visors.

FIG. 1 shows the device in section, general view; in fig. 2 — node I in FIG. one.

20

Claims (2)

The device for abrasive blasting of the inner surface of small-diameter tubes is a tank I filled with an abrasive mixture 2. Inside the tank a nozzle 3 is mounted. Its end 4 with an opening for the abrasive-air stream is located above the upper level 5 located in the abrasive tank and with a gap S in relation to the hole 6 to exit the abrasive air & jet from the tank. In the lower part of the nozzle there is a hole 7 for feeding the abrasive mixture. Inside the nozzle, at the level of the holes 7, a tube 8 with a calibrated hole 9 is mounted for more accurate compressed air supply. The diameter of the calibrated hole 9 should not be less than the diameter of the hole 6 for the air-abrasive mixture to exit the tank into the processed tube 10. The hole 6 can be located in the neck 11 of the tank 1 in different directions (vertically, horizontally and at different angles to the tank axis). The diameter of the hole 6 for the release of the abrasive-air stream from the tank must not be larger than the internal diameter of the pipe 10 being processed. On the outside of the deck 3 above the holes 7, the upper protective visor 12 is mounted at a distance H from the bottom 13 holes 7. HapjoK diameter T) | the upper visor 12 is determined by the following formula: () / where p. is the inner diameter without the level of the holes 7; And, the distance from the bottom of the holes to the peak 12; and the angle of repose of the abrasive. The visor 12 serves to prevent the holes 7 in the nozzle from choking, i.e. not clogged, abrasive. The outer diameter IK of the visor 12 is selected using the above formula. This size is optimal. With a smaller diameter, the holes 7 can be clogged with an abrasive, with a larger diameter it is difficult or the OTCJTT can flow into the nozzle. Outside the nozzle 3 below the holes 7, the lower protective visor 14 is mounted, the diameter of which may be larger than the diameter of the visor 12. The visor 14 may have a funnel profile with the socket pointing upwards. A pipeline 15 is fastened to the bottom of the tank 1 for supplying compressed air to the nozzle 3. The tube 10 to be processed is at one end inserted into the rubber sleeve 16 of the neck 11, and the other into the rubber sleeve 17 of the neck 18 of the tank 19, which is a discharger. About cServes abrasive from an abrasive-air abrasive mixture. A rubber tube (a hose not shown in the drawing) may be put on the tube .10 which is being worn, the other end of which is put on the fitting 20 of the tank 19. The device works as follows. Compressed air is supplied through the conduit 15 to the nozzle 3, since the diameter of the hole 6 for the abrasive-air jet outlet from the tank is smaller than the calibrated hole 9 of the plug 8, an excessive pressure is created in the tank 1. This pressure acts on the abrasive mixture. 2. Compressed air escapes from the tank through the opening 6. Inside the nozzle 3 there is a constant flow of air to the level of the openings 7. Due to the size difference between the diameters of the plug and the part of the nozzle located above the openings 7, an abrasive mixture is sucked in. Compressed air is partially filtered through. the thickness of the abrasive mixture and tends to go into the holes 7, carries with it the abrasive inside the nozzle. Thus, the abrasive mixture 2 enters the nozzle 3 under the action of gravitational forces and the pressure difference inside the nozzle and the pressure in the abrasive mixture in the 7 holes, above which a stream of compressed air is formed, with an abrasive mixture of a certain concentration. This stream emerges from the orifice of the end face 4 of the nozzle 3 in the form of a jet, which forms the plume of the sprayed abrasive mixture in the upper part of the tank 1 in the free space above the level 5 filled in the abrasive tank. The compressed air leaving the tank through the opening 6 captures from the sprayed torch only a part of the grain mixture, which is in the capture zone of the outgoing plume of compressed air at the opening 6, in which a stream of abrasive-air mixture leaving the tank is significantly smaller concentration than the jet coming out of the nozzle. The part of the abrasive that the compressed air torch did not catch returned (falls) into the total mass of the abrasive mixture. A stream of abrasive mixture coming out of the tank passes through the inner cavity of the tube and treats the inner surface in a predetermined mode and is then sent to the tank of the discharger 19 to separate the abrasive from the abrasive-air mixture. After cleaning, the abrasive mixture is transported back to tank 1, and the air after cleaning in the filters (dust collectors) is sucked off by a vacuum system. Since at the outlet from the tank, the abrasive-air mixture has a low concentration, i.e. highly aerated, the probability of the formation of abrasive plugs reduces to a minimum. By changing the distance S between the end face 4 and the opening 6, its weight concentration can be changed. When the outer diameter DK of the upper protective visor 12 according to the formula given above when the device is not working, the abrasive, dumping, theoretically reaches only the internal diameter of the DC nozzle / not the backfill of the calibrated orifice 9 of the plug 8. The lower visor 14 serves to facilitate the flow of abrasive into the nozzle , since the coefficient of friction (adhesion) of an abrasive material on a visor is much smaller than the coefficient of friction between the grains of the abrasive material itself. The use of the described device significantly expands the technological possibilities of processing. Claims The device for abrasive blasting the surface of parts containing an abrasive tank with a hole for taking the abrasive air stream from the tank, and inside the tank there is a nozzle, the upper end of which is located above the level of abrasive in the tank, and with a gap in relation to the hole for the abrasive jet, the nozzle has in the lower part of the hole for feeding abrasive into it, characterized by In order to expand the technological capabilities in processing the inner surface of small diameter parts, the device is provided with a stopper with a calibrating hole, mounted below the level of the abrasive holes to the nozzle, and outside the nozzle above and below the abrasive holes, the protective peaks inserted into the device are mounted. Sources of information taken into account at. examination 1. French patent 1320075, CP. In 24 With,. publ. 1963 (prototype). / 1Z / h: ; j. N kXXXXXI L